Based on the data shown below, calculate the correlation coefficient (to three decimal places). This is the 'r' value you get when you do the regression.
| x | y |
|---|---|
| 4 | 22.08 |
| 5 | 20.1 |
| 6 | 20.12 |
| 7 | 18.84 |
| 8 | 15.96 |
| 9 | 13.18 |
| 10 | 14 |
| 11 | 11.72 |
| 12 | 9.74 |
| 13 | 10.36 |
| 14 | 7.88 |
| 15 | 7 |